My long-term career plan as a physician-scientist is to better understand the mechanisms by which Pseudomonas aeruginosa causes severe disease and to use this knowledge to drive translational research involving prognostic and therapeutic interventions. Such a career path will utilize research skills in both microbiology and infectious diseases but will require a considerable amount of effort. To assure protected time for research, additional salary support through the K02 is needed. The proposed studies will allow us to broaden our research focus by identifying novel pathogenicity islands and genes that account for the increased virulence potential associated with some P. aeruginosa strains but not with others. Subtractive hybridization will be used to compare the genomes of a hypervirulent P. aeruginosa strain and a minimally virulent strain. The genomic loci of genetic elements unique to the hypervirulent strain will be sequenced and compared to the known genome of the less virulent strain to determine the extent of these elements and whether they are indeed unique to the hypervirulent strain. Selected unique genetic elements will then be tested for their ability to augment the virulence of P. aeruginosa. Completion of the experiments outlined in this proposal will lay the foundation for future studies aimed at determining whether identified novel virulence determinants serve as markers for P. aeruginosa strains capable of causing especially severe disease in humans. Such information will have prognostic and therapeutic implications with regard to the management of patients suffering from P. aeruginosa infections. As part of my development as an independent investigator, I will have the opportunity to interact with the members of the Department of Microbiology/Immunology and Medicine at Northwestern University. These interactions will take the form of seminar series, journal clubs, and informal discussions. Also, an ethics curriculum and coursework in statistics and epidemiology is outlined in the application. These plans will provide me with opportunities for enhanced career development by acquisition of new research skills and will be fostered by the strong interdisciplinary research environment at Northwestern University.